BROOMFIELD, Colo.--(BUSINESS WIRE)--ARCA biopharma, Inc. (Nasdaq: ABIO), a biopharmaceutical company
developing genetically-targeted therapies for atrial fibrillation, heart
failure and other cardiovascular diseases, today provided an update on a
proposed, genetically-targeted clinical trial in atrial fibrillation
(“AF”) of the Company’s lead developmental drug, Gencaro (bucindolol
hydrochloride). The Company also announced that Medtronic, Inc., a
leader in medical technologies to improve the treatment of chronic
diseases, including cardiac rhythm disorders, has signed a non-binding
Letter of Intent to collaborate on the initial, Phase 2B portion of the
proposed trial.

The Proposed GENETIC-AF Phase 3 Adaptive Design Clinical Trial

The trial, known as GENETIC-AF, is projected to be a 620-patient, Phase
3 study comparing Gencaro to metoprolol CR/XL for prevention of AF in
patients with heart failure and left ventricular dysfunction ("HFREF").
The Trial is planned to be genetically enriched by enrolling only those
patients who possess the cardiac beta-1 adrenergic receptor genotype 389
arginine homozygous, which in the Beta Blocker Evaluation of Survival
Trial ("BEST") was associated with an enhanced response to Gencaro in
preventing atrial fibrillation. The Company estimates that this genotype
is present in about 50% of the U.S. population. The primary endpoint of
GENETIC-AF is planned to be the combination endpoint of recurrent
symptomatic AF and all-cause mortality, over 24 weeks post electrical
cardioversion for persistent AF. Commencement of the GENETIC-AF is
conditional on receipt of the necessary funding, which ARCA intends to
secure through equity financing or a strategic partnership.

ARCA has created an adaptive design for GENETIC-AF, under which the
Company plans to initiate a Phase 2B study in approximately 200 HFREF
patients. Depending on the results of the Phase 2B portion, the trial
could then be expanded to a Phase 3 study by enrolling an estimated
additional 420 patients. A secondary endpoint of the proposed Phase 2B
portion of the trial will be AF burden, defined as a patient’s actual
time in AF, regardless of symptoms. Under the Company’s proposed design,
all 200 patients in the Phase 2B portion of the trial will have AF
burden measured by continuous monitoring, either by previously implanted
cardiac resynchronization or defibrillation devices, or newly or
previously inserted implantable loop recorders. At the end of
enrollment of the first 200 patients, the primary endpoint of recurrent
symptomatic AF and all-cause mortality, and the secondary endpoint of AF
burden will be evaluated by the trial’s Data and Safety Monitoring Board
for evidence of an efficacy signal. If a sufficient efficacy signal is
detected and acceptable safety is observed, the trial would then proceed
to the Phase 3 portion and full enrollment.

ARCA believes that Gencaro has potential as a treatment for AF, based on
placebo-controlled data from the Phase 3 heart failure BEST study. A
retrospective analysis of data from the BEST Trial shows that patients
with the genotype that ARCA plans to enroll in GENETIC-AF had a 74%
reduction in the risk of AF compared to placebo (p = 0.0003). These same
patients experienced a 38% reduction in the risk of all cause mortality
(p < 0.05) and statistically significant improvements on other major
clinical efficacy endpoints.

AF is considered an epidemic cardiovascular disease with an estimated
prevalence of at least 2.7 million Americans in 2010. In HFREF patients,
the approved therapies for the treatment or prevention of AF have
disadvantages, such as toxic or cardiovascular adverse effects, and most
of the approved drugs are contra-indicated or have warnings in their
prescribing information. ARCA believes there is an unmet medical need
for new AF treatments that are safe and more effective in the HFREF
population at risk for AF.

ARCA has received guidance from the Food and Drug administration (“FDA”)
regarding a Phase 3 clinical study comparing Gencaro to metoprolol for
the prevention of AF in approximately 600 HFREF patients, with a design
similar to GENETIC-AF, but without an adaptive feature. Based on this
FDA guidance, the Company believes that a successful Phase 3 clinical
study similar to GENETIC-AF, with a p-value of less than 0.01, could be
sufficient evidence of efficacy upon which to base a New Drug
Application (“NDA”) for the approval of Gencaro for an AF indication in
HFREF patients. ARCA plans to obtain further guidance from the FDA,
which may affect the trial’s design.

The proposed collaboration with Medtronic involves a substudy of the
Phase 2B portion of GENETIC-AF that will measure the AF burden data by
means of the continuous monitoring devices. Under the proposed
collaboration, Medtronic would provide support associated with the AF
burden substudy and with collection and analysis of the substudy data.

Dr. Michael Bristow, MD, PhD., President and Chief Executive Officer of
ARCA, said, “We at ARCA are excited about the new adaptive design for
GENETIC-AF and the potential to use AF burden measured by previously
implanted devices as well as by newly inserted implantable loop
recorders, which we believe represent the next generation of diagnosis
and treatment options for patients at risk for AF. AF is a serious
disorder that increases the risk of stroke and mortality, and in HFREF
patients often heralds the worsening of heart failure. There is a need
for new treatment options, particularly for patients with HFREF. The
GENETIC-AF trial has the potential to result in an approvable new
therapy that is safe and effective for HFREF patients at high risk for
AF. We believe that the use of continuous monitoring devices including
implantable loop recorders to monitor AF burden in the Phase 2B substudy
will result in many more clinically-relevant events, which will
potentially increase the power and usefulness of the data. We believe
that AF burden used in conjunction with drug therapy will become an
increasingly important tool in the diagnosis and treatment of AF.”

About ARCA biopharma

ARCA biopharma is dedicated to developing genetically-targeted therapies
for cardiovascular diseases. The Company's lead product candidate,
GencaroTM (bucindolol hydrochloride), is an investigational,
pharmacologically unique beta-blocker and mild vasodilator being
developed for atrial fibrillation. ARCA has identified common genetic
variations that it believes predict individual patient response to
Gencaro, giving it the potential to be the first genetically-targeted
atrial fibrillation prevention treatment. ARCA has a collaboration with
the Laboratory Corporation of America (LabCorp), under which LabCorp has
developed a companion genetic test for Gencaro. For more information
please visit www.arcabiopharma.com.

Safe Harbor Statement

This press release and the associated presentation may contain
"forward-looking statements" for purposes of the safe harbor provided by
the Private Securities Litigation Reform Act of 1995. These statements
include, but are not limited to, statements regarding the ability of
likelihood of completing a definitive agreement with Medtronic for
support of the planned trial, genetic variations to predict individual
patient response to Gencaro, Gencaro’s potential to treat atrial
fibrillation, future treatment options for patients with atrial
fibrillation, the number of events recorded by implantable loop
recorders, the role of AF burden in diagnosis and treatment of atrial
fibrillation and the potential for Gencaro to be the first
genetically-targeted atrial fibrillation prevention treatment. Such
statements are based on management's current expectations and involve
risks and uncertainties. Actual results and performance could differ
materially from those projected in the forward-looking statements as a
result of many factors, including, without limitation, the risks and
uncertainties associated with: the Company's financial resources and
whether they will be sufficient to meet the Company's business
objectives and operational requirements; results of earlier clinical
trials may not be confirmed in future trials, the protection and market
exclusivity provided by the Company’s intellectual property; risks
related to the drug discovery and the regulatory approval process; and,
the impact of competitive products and technological changes. These and
other factors are identified and described in more detail in ARCA’s
filings with the SEC, including without limitation the Company’s annual
report on Form 10-K for the year ended December 31, 2011 and subsequent
filings. The Company disclaims any intent or obligation to update these
forward-looking statements.